What happens during ovulation?
During ovulation, a surge of luteinizing hormone (LH) makes the most mature follicle in one ovary burst and release its egg. The egg is swept into the fallopian tube, where it can be fertilized for about 12 to 24 hours. The empty follicle then becomes the corpus luteum and starts making progesterone. It usually happens 12 to 14 days before your next period.
Ovulation, step by step
- The build-up: over the follicular phase, one follicle grows bigger than the rest and pumps out estrogen.
- The trigger: when estrogen is high enough for long enough, the brain releases a big surge of LH. This is what home ovulation tests detect.
- The release: about 24 to 36 hours after the LH surge begins, the follicle wall breaks and the egg is released.
- The catch: finger-like ends of the fallopian tube sweep the egg inside.
- The wait: the egg can be fertilized for roughly 12 to 24 hours. Sperm can survive up to about 5 days, which is why the fertile window starts before ovulation.
- The switch: the empty follicle turns into the corpus luteum and starts making progesterone, beginning the luteal phase.
What you might notice
Many people feel nothing at all. Others notice a few signs in the days around ovulation:
| Sign | Why it happens |
|---|---|
| Clear, stretchy, egg-white discharge | High estrogen thins cervical mucus |
| A one-sided twinge or ache (mittelschmerz) | The follicle stretching or releasing the egg |
| Light spotting | A brief estrogen dip around ovulation |
| Higher sex drive | The estrogen and testosterone peak |
| Small temperature rise after ovulation | Progesterone raises resting body temperature |
| Breast tenderness | Hormone shifts, more common just after ovulation |
See signs of ovulation for more on each, and what ovulation discharge looks like for the most useful one.
When ovulation happens
Ovulation usually happens 12 to 14 days before your next period, not on day 14 of every cycle. In a 28-day cycle that's around day 14 to 16; in a 35-day cycle it's closer to day 21. A large study of connected ovulation tests found a 10-day spread in ovulation days even among people with 28-day cycles. Our ovulation calculator gives an estimate, and how to track ovulation shows how to pin it down.
Occasional cycles without ovulation are common, especially in the teenage years, around perimenopause, during stress, and with PCOS. You can still bleed in those cycles.
Ovulation and how you feel
The days around ovulation are often the high point of the cycle: estrogen peaks, and many people feel more social, confident and energetic. After ovulation, progesterone rises and some people feel calmer, sleepier, or, later in the luteal phase, more sensitive. Our page on ovulation mood goes deeper.
See a doctor if ovulation pain is severe or lasts more than a day or two, if you have pain with fever or vomiting, if your cycles are often longer than 35 days, or if you've been trying to conceive for 12 months (6 months if you're 35 or older).
Frequently asked questions
How long does ovulation last?
The release itself is quick. The egg then survives about 12 to 24 hours. See how long ovulation lasts.
Do both ovaries release an egg every month?
Usually only one egg is released per cycle, from either ovary. Occasionally two are released, which is how non-identical twins happen.
Can you feel the moment you ovulate?
Some people feel a twinge on one side, called mittelschmerz, but it doesn't always line up exactly with the egg's release.
Where does the egg go if it isn't fertilized?
It breaks down and is absorbed by the body. It isn't something you see in your period.
Sources
- Cleveland Clinic: Ovulation
- Soumpasis I et al. Real-life insights on menstrual cycles and ovulation using big data. Hum Reprod Open (2020)
- NHS: Fertility in the menstrual cycle
This page is for information only and isn鈥檛 medical advice. If something worries you, please talk to a doctor.
Keep reading
Ovulation phase: signs, timing and feelingsThe ovulation phase explained: when you ovulate, how long it lasts, the signs and symptoms to look for, and why mood, energy and libido often peak.
What are the signs of ovulation?Signs of ovulation: egg-white discharge, a positive LH test, a temperature rise, one-sided twinges and higher sex drive. What each means and how to read them.
When do you ovulate?When do you ovulate? Usually 12 to 14 days before your next period, not always on day 14. How to estimate it and the body signs that confirm it.
How do you track ovulation?How to track ovulation: calendar estimates, LH tests, cervical mucus, temperature and wearables. What each tells you and how to combine them.Ovulation calculator: when do I ovulate?Free ovulation calculator: enter your last period and cycle length to see your likely ovulation day for the next 4 cycles. Private, instant, estimates only.